STATE COLLEGE OF WASHINGTON 
PULLMAN, WASHINGTON 


EXTENSION SERVICE 
W. S. Thornber, Director 


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o” Fuel Economy in Domestic 
Heating and Cooking 
By 


B. L. STEELE, 


Professor of Physics 


Division of Mechanic Arts 


and Engineering 


The State College of Washington 


and 
de U. S. Department of Agriculture 
Cooperating 
December, 1917 
+4 oot 5 
Séries I ; No. 382 


® 


LETTER OF TRANSMITTAL 


Pullman, Washington, December 15, 1917. 


Director W. S. Thornber, 
Extension Service, 
State College of Washington. 


Sir: I have the honor to transmit herewith a bulletin on the 
subject, Fuel Economy in Domestic Heating and Cooking. This 
bulletin has been prepared by Professor B. L. Steele at the request 
of the faculty of the College of Mechanic Arts and Engineering. In 
view of his experience with a wide variety of experimental work in 
this field extending over the past ten years, I feel that his con- 
clusions may be accepted with the fullest confidence. 

Very respectfully, 
H. V. Carpenter, 
Dean, College of Mechanic Arts 
and Engineering, The State 
College of Washington. 


ai 


INTRODUCTION 


The United States Geological Survey estimates that the coal 
production in the United States for the year 1917 will probably 
exceed that of 1916 by more than 50,000,000 tons, and yet Dr. 
Harry A. Garfield, United States fuel administrator, announced re- 
cently that the increased use of coal in munitions factories and 
other war enterprises would entail a net shortage in the United 
States for the year of more than 50,000,000 tons and that this 
shortage must be made up by further increased production, cur- 
tailment of nonessential manufactures, and reduced consumption in 
the homes. It is further estimated that of the 650,000,000 or more 
tons which will be produced in 1917, approximately 125,000,000 will 
be used for domestic heating and cooking. During 1918, therefore, © 
the consumption in the homes must be so reduced as to save probab- 
ly as much as 15,000,000 tons. This bulletin is written in the hope 
that it may assist the people of the State of shes in doing 
their share in this AE te 


ih 


COMPARATIVE DATA CONCERNING FUELS 
AND THEIR USES 


Tables I. and II. give important information concerning fuels, 
which are fairly representative of those used in the State of Wash- 
ington. This information should be valuable in purchasing and using 
fuel. Attention should be called to several considerations in con- 
nection with the items in the tables. In the first place, other 
things being equal,—e. g. cost, convenience in handling, and effi- 
ciency obtained in firing, that fuel is best which yields per pound, 
when burned, the largest number of units of heat—B. T. U.’s* 
Notwithstanding this fact, that particular coal which happens to 
yield when burned, the largest bulk of ash, is rated by many as 
the poorest coal, regardless of its other characteristics. Aside 
from the annoyance of having to handle the ashes, they are an ad- 
vantage rather than a disadvantage, so far as the economical burn- 
ing of the coal in stoves or house heaters is concerned, unless 
the percentage of ash is exceedingly high, above 10% to 12%. Fur- 
thermore, a little study of the table will show that the percentage of 


*British Thermal Unit is the heat unit most used in engi- 


neering practice and is the quantity of heat absorbed by a pound 
of water when its temperature is raised one degree Fahrenheit. — 


moisture in the coal, which is not apparent directly to the purchas- 
er or user, is perhaps of more importance in determining the value 
of coal than is the percentage of ash. The analyses given are taken 
from the reports of the United States Geological Survey and are for 
samples “as received” from: the mine.: The tests of Canadian coals 
are not official, but are apparently reliable. Attention is called to 
the four analyses of the sample of Mendota coal. These analyses 
show that in considering the analysis of a coal it is necessray to 
know whether the analysis was made “as received,” “air dried,” 
“dry coal,” or “pure coal.” aed 


The fuel value of wood depends so much on whether it is 
green or dry that it is difficult to give a dependable statement of 
the heat equivalent of a pound of wood. However, 5800 B. T. U.’s 
per pound, the value given in the tables, is a good average for fair- 
ly dry Washington woods. Also, the weight of a cord of wood is a 
widely varying quantity, ranging from about 2100 pounds for dry 
pine to 3800 pounds. for green tamarack. The average is probably 
about 2700 pounds per cord of well. seasoned: wood. 12,000 B. T. 
U.’s per pound may be taken as the average fuel value of the coals 
used in Washington: Hence, if wood and coal may be equally effi- 
ciently burned, a ton of coal is approximately equivalent in heat- 
ing value to a cord and a half of wood. 


When an electric current is used for heating, one kilowatt- 
hour of electric energy generates 3412 B. T. U.’s of heat. 


Tests have shown that when a good grade of soft coal is 
burned in the ordinary warm air, steam, or hot water heaters used 
for residence heating, under the widely varying conditions demanded 
by the weather, and with the promiscuous methods of firing com- 
monly used, on the average not more than 30% or 40% of the fuel 
value of the coal is utilized in heating the house. When anthracite 
coal, or any other fuel which has a high percentage of fixed carbon, 
is burned in a heater which has been properly installed and is eco- 
nomically fired by a competent fireman, the efficiency attained is 
between 50% and 60%, while with poor grades of coal and with in- 
correct installations and careless methods of firing, 75% or more, 
of the coal is wasted. In burning wood the efficiency is about the 
same as in burning a good grade of soft coal. Although in house- 
heaters lump coal may be burned slightly more efficiently than the 
finer sizes, the finer sizes are more economical usually because of 
the lower prices. at, which they may be purchased. When electri- 
city is used for heating the efficiency is practically 100%. _. 


TABLE I. 


Mois- Volatile Fixed Ash Baie 
Name ture Matter Carbon 
Washington Coals 
HISSATHaANG: ae se es, ee Dek 29.4 44.2 11.35 9.960 
Grand “Ridge ..) .. 7. 16.5 34.6 36.4 12.5 9.580 
EVCINEODOr rs crsuls ckrie sap e ol 4s 6 34.0 41.5 9.9 10.070 
Bikwe Diamond: s.: <. (hse! Done 49.2 4.07 12.500 
Ost yin OCASCAGe cnc cl nce ol 35.6 50.0 12%. 12.850 
HeOsly pn Ue COn sa) we) ao 34.1 50.5 5 ES 12.910 
OO ELUM Esle Week wrote ts ot oD 34.6 44.8 12.68 11.410 
Neo EVV eI tc COsr se ea aes Oo ak 35.6 49.9 12237 12.860 
WilkeesOn. t+ sees Seat oT 56.6 12.60 12.980 
Carbonadoar eS. sere.) 7 3'8 mathe k Jom C 15.37 UAC Rey) 
Wingate .. 4.0 36.9 Swath 6.41 13.280 
Mendota 
AS received °.. ...20.5 Some Sout L223 8.690 
ATLWOTIC das at toa.) O's 2 Sif h cits) Yoho dk 13.91 9.820 
DPV COGMT sade Wo oie) + 42.1 42.4 10.920 
Pre COMM. sss 49.8 50.2 12.940 
Utah Coals 
GastlersGate. 2.4 ...0e aos Gels 40.07 45.45 8.35 12%, 217 
ELGIDCTARS A. se cs le tak) ae ed 40.79 49.98 4.76 12.982 
iGsos A Se eG epee oes 42.02 47.06 4.87 Toro 
Wyoming Coals 
Rock Springs : 
Witt NOL Leos sie eto 35.6 50.39 5.48 11.833 
Ure PueNon- LO lems. » oe lL 36.57 48.5 74? 11.920 
Kemmerer fica slot ks Boone — Se) ee hs) 51.0 3.65 12.784 
Od Creeke owe vomwmacie. © ltd 35.53 45.10 74 3383 10.991 
Montana Coals 
Rear “Creek 2.3. fo bee 8.74 35.99 45.72 10.55 10.604 
rea WOdsSeu nile el bon ete Go 36.14 40.19 11.98 9.787 
FLOUMC eL Iso: hain crete Peo 28.0 51.8 Bye) 11.050 
Canadian Coals 
Greene Ey (ees tucks ts elt. 23.4 63.8 alla 13.700 
CHOVES NCS tie ris siete oa keel 22.6 64.9 1T2a5 13.270 
Corbin Bye 25.5 59.0 12.0 13.000 
Wood (Average Washington WoO0dS): ws recess nccvsans Reet enaikereer sie ; 5.800 
FEET OSCTIC ate sic oss milone te ote SPARES Ra achAie Pea cits Nika ie rar ie gt a ri 19.980 
A SOU Coy karorar oe ersveX eke wamenrs Wed Mc oaree MONT Renee tek attters ta) tals emer aa «heey Ohl 20.250 
MIGGUrLCItye (ost lom ss DCG Ki MOWALREDT 3) ve ots ois cio ante sitios wroetaene ead. « 3.412 
ES COR L ersten Clem Dein CXL. ml CR areca ote e erable. Wi acah slabs Sue ate bead a renehe ates eres 6 600 
TABLE II. 
Fuel — | Utilizable 
Fuel Price Value. B.T.U for |mfficiency | B.T.U. for 
B.T.U. $1.00 lof heater $1.00 
COALS a. sca; 3 $10.00 per ton 12,000 ..| 2,400,000.) . 35% « 890,000 
WiOOds.s ..+-)510..00 pér cord | 5,500 1,595,000 | 35% TASTE HGAL 
Electricity.,| le per KWhr.| 3,412 341,200 | 100% 341,200 
Electricity. .|%e per KWhr.| 3,412 682,400 | 100% 682,400 


The following tables give useful information concerning 
kitchen fuels, efficiencies of cooking equipments, and cooking costs 
with various fuels. They summarize in part the results of some 
tests made during the past two or three years at the Home Eco- 
nomics Practice Cottage of the State College of Washington by the 
seniors in Home Economics. 

Table III. gives the number of B. T. U.’s in one dollar’s worth 
of each of the “fuels” used for cooking. 


TABLE III. 
Kind of Fuel B. T. U.’s for $1.00 
(Oxveysul GN SAMs OU) TXeNe Won” son nbooouddoo Ge pees told 2400000 
IWiOOUm @ ao OMG OND ete COC Mere sirerele tele tehanene ateteke one 1595000 
eepeorieuate: (@) PANE: Teyere ee VIO Go ano oo oo bus te et oeleniO MOO GAO 
Gasoline 2@i.25¢e epee Sa llom ae wus oe oletele et onemetere > 49250 
HIeECtriCGity, @  secoe per ilowatt soe oe ea a ao OFS 
Mlectmicitya@es 6 Dera KOA 1d wisi ees enenras 113730 


*Prices in Pullman, Washington in. December, 1916. 


Table IV. gives the averages of a large number of tests on 
the efficiencies of various kinds of cooking equipment. 


TABLE IV. 

Kind of Equipment Efficiency 
CoalswRange, (entires space Witill Zed) mei. i-tieiete ner nee 18% 
Coal Range, (estimated for home cooking) about .. 2.5% 
Flame contact burners (kerosene, gasoline) about 25% ; 
Mlectrie, heaters) SuriaCe sm. kic a circ aemene annette 45% to 65% 
Hilectrie heaters: = en CloSeG.) wisn. susie euch ronsteiencnench ener amc 10% 
HMlectric, Heavers, ey VmMniee Silom ee await nemesis teehee tncnee aaa 90% 


Table V. gives the B. T. U.’s which are actually used when 
_one dollar’s worth of each of the “fuels” is burned, the various 
ranges operating at their average efficiencies. 


SLAB Lites 
Fuel Avreage B. T. U.’S 
Fuel for $1.00 
Comlwm(ransenat 2.5% Cli ClENM Cy.) oe asaree eae 60000 
Wood, (range at) 2-59, (elficiency) 5 vss... oshame 39875 
Kerosene (range at 25% CLHCIEN GY) 21 ct-ees ee oe 169640 
Gasoline (range at 25% CL ficiency Me. see ein 123215 
Electricity (67% efficiency at 3.85 cts. per 
LCLlO Watt hitter et. esis Goat ns eee 59380 
Electricity (67% efficiency at 3 ets per 
Kalo Wa tla eho ceteris chore eee ie eh: mete 76200 
TABLE VI. 
Cost of Cooking for Family of Five 
Equipment Average Cost 


Coal Range, (water front connected*) ........119.6 cts 
Coal Range (water front disconnected) ...... W174 ets. 
TGLECELLC MAEVE 2 Ulnar a sant Da ence eccice eee ed eee ee a eeis elon OMGESS 


*Coal at $10.00 per ton; electricity at 3.85 cts. per Kilowatt hour. 


6 


In table VI., is given the cost of cooking for a week for five 
persons on the electric range, on the coal range with the water 
front disconnected and on the coal range with the water front 
connected. Each value is the average of the results for several 
weeks’ cooking. It may be observed that it cost 42.2 cents a week 
to heat the water for domestic use for this family of five with the 
water front on the coal range. These results were obtained during 
1916-1917. 


Ls 
HOW TO SAVE COAL IN DOMESTIC HEATING 


Coal may be saved in domestic heating by using fuels other 
than coal, by heating only part of the house, by preventing un- 
necessary heat losses, by proper choice of heating equipment, by 
following correct practices in installing the heating equipment, and 
by following economical methods of operating it. 


Using Fuels Other than Coal 


At present prices, in the State of Washington, wood is prac- 
tically the only fuel other than coal available for residence heating. 
Its use in those sections where it may be had locally is urged, for 
its use not only saves coal, but also saves transportation facilities. 
The local price in some sections may be such as to make it more 
expensive than coal. Reference to table II. above will enable one 
to calculate the prices for coal and wood which are equivalent. Re- 
gardless, however, of the relative cost of wood and coal, the use 
of wood, wherever possible, should be looked upon at present as a 
patriotic duty. 


From the last column in table II. it may be seen that to heat 
a house with electricity at % cent per kilowatt-hour it costs about 
50% more than to heat it with coal at $10.00 per ton. The use of 
electricity for heating is, therefore, for most families not practi- 
cable at present. 


The relative value of these fuels at any other prices may be 
easily calculated. 


Heating Only Part of the House 


While it is a great convenience to have all the rooms of a 
house heated all of the time, it is to be regarded as a wasteful ex- 
travagance in the present crisis, for on the average it takes he- 
tween a ton and a ton and a half of coal to heat one room in an 
ordinary house during the winter heating season. If during the 
period of the war every family, living in a large house, heated regu- 
larly only those rooms actually needed, thousands of tons of coal 
would be saved in a year in the State of Washington alone, 


7 


Preventing Unnecessary Heat Losses 


In cold weather it is necessary to add heat to the rooms of 
a house continually in order to keep them warm because heat is 
continually and in part unavoidably escaping from the house to the 
outside; first, by direct transmission through the walls, windows, 
and doors; second, by the passage of warm air out through ventilat- 
ing or stove flues; and third, by the filtration or diffusion of warm 
air through the walls and by the leakage of warm air out around 
doors and windows. The direct loss of heat, by conduction through 
a square foot of window, is four times as great as that through a 
square foot of wall of ordinary wood construction; hence a large 
part of the direct loss is prevented by using double glazed windows 
or by simply providing the windows with tightly fitting storm sash 
during the heating season. 


In order to provide fresh air in the living rooms, part of the 
loss due to filtration through the walls and leakage around the 
doors and windows is necessary, but with the ordinary house con- 
struction the loss due to leakage around doors and windows is far 
more than necessary, particularly during windy weather. The 
storm sash just mentioned will prevent sufficiently the leakage 
around the windows, but if they are not used, the windows and 
doors should be provided with weather strips of some kind. 


The amount of heat lost per hour from a house depends on 
the difference between the inside and outside temperatures. With 
an average outside temperature of 40° Fahrenheit, which is nearly 
the average temperature for the State of Washington from October 
to May, the amount of coal necessary to maintain a temperature of 
68° is about 15% less than that to maintain a temperature of 72°. 
The average winter residence temperature in the State of Washing- 
ton is probably about -72° or 73°; and it might be reduced to 68° if 
sufficient effort were made to humidify the air, for the amount of 
invisible moisture in the air determines to some extent the tem- 
perature at which a room seems agreeably warm. Dr. Henry Mitch- 
ell Smith makes the following statement as the result of many ob: 
servations and experiments upon the sensations produced by dif- 
ferent temperatures and percentages of saturations: “It may be 
accepted as a cardinal rule that if a room. at 68° is not warm 
enough for any healthy person, it is because the relative humidity 
is too low.” It has been found that for comfort at 68° the relative 
humidity must be about 44%. Much lower relative humidities are 
not only uncomfortable, unless accompanied by excessively high 
temperatures, but they are also detrimental to health. To bring 
the indoor relative humidity up to 44% in the drier sections of the 
State will require the evaporation of ‘several gallons of water each 
day in the living rooms of the ordinary house. The saving of coal | 
made possible and the effects beneficial to health which result 


make worth while any effort to humidify the air in living rooms 
during the heating season. 

A very considerable saving of fuel may therefore be effected 
by the use of storm sash and weather strips, and by maintaining 
room temperatures 4° or 5° cooler than usual. 


Proper Choice of Heating Equipment 


The considerations presented here are of general interest, but 
are not especially helpful in the present situation, because in most 
cases the heating equipment is already installed. 

The open fireplace is the most wasteful of all types of heat- 
ing equipment. Its efficiency is probably never greater than 10% or 
15%. It serves a good purpose on cool mornings and evenings and, 
when in use, is a good ventilator, but its artistic and aesthetic 
values furnish the chief justification for its existence in nearly any 
home. 

If only one or two rooms of the house are to be heated, the 
heating may be done very economically with any one of the many 
excellent stoves on the market. One of,the newer types in which 
special provisions are made for more complete combustion of fuel 
and for more nearly perfect control of the fire, and in which large 
radiating surfaces are provided, will give more economical results 
than some of the older forms. The stove should have a reversible 
grate if it is to be used for either coal or wood. 

When the house is large and many of the rooms are to be 
heated much of the time, it is safer, cleaner, more convenient and 
probably more economical to use some kind of central heating plant. 
If the house is not too large, a warm air furnace properly installed 
is quite satisfactory, but for very large dwellings a hot water or a 
steam heating system will generally give better results. The first 
cost of a warm air furnace is much less than that of a hot water 
or steam heating system, but the life of either the steam or hot 
water equipment is usually considered to be several times that of 
the warm air furnace. Each of the types has some advantages over 
either of the others, but if they are properly installed and operated 
there is perhaps not very much difference in their fuel economies. 


Installing and Operating the Heating Equipment 


An essential part of any heating plant, no matter how simple 
or small, is a chimney of such size and height as to furnish an ade- 
quate draft. It is much better to have too much than too little 
draft, for proper use of dampers makes it posssible to control the 
fire in the former case, but not in the latter. Insufficient draft 
results in sluggish fires and often in the clogging up of the stove 
pipe or flue. To -avoid trouble from wind blowing down the chim- 
ney, the Spinney eon extend: SEs feet sabe the ee part 
of the roof.: ; 


In order that the draft may be properly controlled, it is 
necessary that all doors and dampers should fit practically air 
tight when closed; and in the case of furnaces, all cracks around 
the base or between sections or parts should be carefully puttied 
or cemented shut. Also a shut-off damper should be placed be- 
tween the heater and the check draft door, or damper. 


Some of the heat of the fuel is necessarily used in creating 
the draft. It probably amounts necessarily to 15% or 20%, but in 
many cases, due to improper methods of firing, a much larger frac- 
tion of the total heat of the fuel escapes up the chimney. Some 
of this chimney waste may be prevented by placing the heater as 
far from the chimney as the quality of the draft and the available 
space will permit and using a long smoke pipe to connect up the 
heater. This is particularly applicable to furnace installations, If 
the draft is sufficient and the firing is correctly done, the smoke 
pipe will keep itself clean and will furnish enough heat to keep 
the furnace room warm. Unless it is desirable to heat the rest of 
the basement, the heater itself and all hot water or steam pipes 
or warm air ducts run in the basement should be properly covered 
with a suitable insulating material. 


It is highly important in heating with warm air furnaces that 
provision be made for the re-circulation of the air. A simple calcu- 
lation will show that if the air is all taken in through the furnace 
from the outside it will take about a third more fuel than if the 
air is re-circulated. 


To burn completely a pound of practically any of the coals 
used in the Northwest for domestic heating, approximately 160 
eubic feet of air must be supplied to the fire. If less air is sup- 
plied the combustion is incomplete; if more air is supplied it is 
heated to a relatively high temperature and passes on up the chim- 
ney. In either case a serious loss of fuel may result. To insure 
complete combustion it is necessary to provide from 20% to 50% 
excess of air, but in many instances where holes are allowed to 
burn through the fire bed, or where doors and dampers do not fit, 
two or three times too much air may be used. This entails an ad- 
ditional chimney loss of probably more than 25% of the entire heat 
of the fuel. The following suggestions for firing apply either to 
stoves or furnaces and if observed will minimize most of the fuel 
wastes. 


An even, steady fire should be kept during the part of the 
day and night when it is desired to have the house comfortably 
warm, between 65 degrees and 70 degrees Fahrenheit. The amount 
of coal fired and the amount of draft allowed will depend on the 
quality and kind of coal used and on the difference between the in- 
side and the outside temperatures. In mild weather, a deep bed 
of ashes should cover most of the grate as it will tend to prevent 
too much air from getting through the grate. In severe weather 


10 


the ash bed should be thinner and the bed of burning coal corre- 
spondingly thicker. 

Whenever firing is necessary, and it should, if possible, al- 
ways be done before the fire has burned too low, most of the glow- 
ing coal should be pushed to the back part of the fire pot and the 
fresh coal thrown into the front part near the feed door, leaving 
the bulk of the burning coal exposed, or to avoid moving the burn- 
ing coal, the fresh coal may be fired alternately on opposite sides 
of the fire pot, particularly if the fire pot is circular. A large 
part of the volatile portion of the coal is driven off during the 
first half hour after firing, (particularly. if small sizes of coal are 
used, or if the coal is non-coking,) and is ignited by the burning 
coal in the back part of the fire pot. This is important, for, if the 
fire happens to be completely covered with fresh coal, a large 
portion of this gas, which may represent a considerable frac- 
tion of the total heat of the coal, escapes unburned before the fire 
burns through and ignites it. And when it does burn through 
an undesirable explosion usually accompanies the ignition of the 
gases. Frequent explosions are indications of careless firing. 


In heavy firing with coals rich in volatile matter, it is some- 
times necessary to open the damper in the feed door for ten or 
twenty minutes just after firing to admit sufficient air to burn 
completely the large quantity of gases given off. In some stoves 
and furnaces a special so-called hot-blast damper is provided which 
is partly intended to serve this purpose. After these gases 
have been burned, the fire should be controlled largely by opening 
the check damper and by partly closing the shut-off damper rather 
than by completely closing the draft damper in the ash pit door, be- 
cause this procedure tends to limit the leaking of air into the fur- 
nace around the feed door, if it does not fit properly, and through 
other small passages above the fire. It will probably be necessary 
also to close completely the ash pit draft damper in mild weather 
or on exceedingly windy days. With this method of control what- 
ever air enters the furnace passes up through the fire. Except in 
emergencies the fire should not be checked by opening the feed 
door. 


Firing should occur at fairly regular intervals, and with 
western coals, though less convenient, it will be found more eco- 
nomical to fire five or six times a day than to fire two or three 
times a day. Enough fire should be provided for the night to keep 
the house from cooling off too much, but it is poor economy to 
keep it as warm through the night as through the day, merely to 
avoid having to warm it up in the morning. 

Frequent shaking of the grates till the fire shows through 
into the ash pit, is likely to result not only in an excess of air, but 
also in loss of unburned coal into the ash pit, particularly if fine 
coal is being used; therefore excessive shaking of the grates should 


li 


be avoided: As a general rule, the fire should be ‘poked very little 
from above unless a badly caking coal is used. 

To insure free access of air to all parts of the grate and to 
prevent overheating of the grate bars by the accumulation of 
ashes up against them, the ashes should be removed every day, 
particularly when Washington coals are used, for nearly every one 
of them has a high percentage of ash. All surfaces over which the 
smoke and hot gases pass should be cleaned at least daily to pre- 
vent the accumulation of soot and ashes, for soot and ashes are 
very poor conductors of heat. This is particularly important in 
steam and hot water heaters. A layer of soot .01 inch thick is as 
effective in preventing the flow of heat from the hot gases to the 
water, as a layer of iron ten inches thick. 

In general these same considerations apply to heating with 
wood. Owing, however, to the small amount and fineness of the 
ash and the coarseness of the wood, the control of the fire is more 
difficult. If wood is burned on a coal grate, it is generally neces- 
sary to close up completely a considerable part of the grate. 


ik 
HOW TO SAVE COAL IN COOKING 


Although in general, coal may be saved in cooking in the same 
ways that it may be saved in heating, it is desirable to call special 
attention to the savings which may be effected by properly han- 
dling the kitchen fire and by using fuels other than coal for cooking. 


Care of the Kitchen Fire 


The fire box of the ordinary kitchen range is built large 
enough to carry a heavy continuous fire, such, for example, as is re- 
quired by a large family on days when ironing and baking are being 
done. To make it smaller, so as to adapt it to the daily use of the 
average family, and to make possible better control of the draft, 
the grate should be kept covered with a thick layer of ashes. At 
some one place, at either one end of the grate or the other, or along 
the side next to the water-front, as the conditions may seem to 
require, the ‘ashes should ‘be raked thin, partly exposing a small 
area of the grate. Through this part of the grate most of the 
necessary amount of air will enter the fire, and over it the thick- 
est part of the relatively small ‘fire should be maintained, never 
allowing a hole ‘to be burned through the fire bed. If a hole is 
allowed’ to burn through the fire the air passes largely through the 
hole, not through the fire, and the fire may actually go out. The 
thick bed of ashes brings the bed of glowing coals up near the top 
of the range. where it.is. most.effective.. If a. fire is desired over a 
considerable length of time, fresh coal: should: be:added while ..nere 
is. yet. a. liberal: supply. of. glowing. coal, much: of: which should: be 


1) 


pushed away fromthe thickest part of the fire and.left uncovered 
to ignite the gases which escape from the fresh coal just after 
firing. ; 

The grate should be shaken lightly, if at all,. most of the 
clearing of the grate being done with a poker at the time of 
starting a fire; and it should be dumped only when. the accumula- 
tion of clinkers is such as to make it necessary, and then it should 
be re-covered at once with a bed of ashes. For the reason ex- 
plained on page 11 it is important that the space above and below 
the oven should be cleaned frequently to avoid. the accumulation of 
soot and ashes. 

When the range is fired in this way the. excess of air ad- 
mitted to the fire is probably not more than is necessary; most of 
the volatile matter in the coal is effectively burned; the combustion 
of the fixed carbon is practically complete; very little unburned coal 
gets through the grate into the ash box; and the amount of coal 
used is, therefore, as small as it could be to accomplish the de- 
sired result. On the other hand, when the coal is burned on 4 
grate practically free from ashes, as it often is, and perhaps with 
holes burned through the fire leaving the bare grate exposed, three 
or four times too much air passes through the fire box; the tem- 
perature of the burning coal and gases may be much reduced and 
the combustion incomplete, resulting in much smoke and soot; and 
although, if there are no holes. in the fire-bed, the fire may be a 
roaring hot fire, in any case two or three times as much Coal is 
burned as is necessary. 


Fuels Other than Coal for Cooking 


The burning of coal in the kitchen range for cooking. pur- 
poses alone is a very wasteful operation; for, in the first place, 
usually only a small part of the heating surface of the top of the 
range and of the oven is utilized, and in the second place a con- 
siderable fraction of the coal is burned either before the cooking 
is begun or after it is finished. Tests made at the State College of 
Washington indicate that the average cooking efficiency of the 
kitchen range is between 2% and 3%. MHence, not only at the 
present time because of the needs of the war situation, should fuels 
other than coal be used for cooking, but also at any other time, 
particularly if they may be used more efficiently. 

Either cord wood or mill wood suitable for the kitchen range 
is available at present in many localities in the state. As a war 
measure, the complete substitution of wood for coal in such lo- 
calities is urged, unless some other more suitable substitute is to 
be had. At any other time, the use of wood for light, quick fires, 
and of coal only where a heavy fire is needed for a considerable 
length of time will probably be found to be more economical than 
the exclusive use of either one alone, and, at least during the sums 
mer months, much more desirable. 


13. 


|W 


Kereseme is an excellent substitute for coal. The newer stoves 
for burning it, have a cooking efficiency of about 25%; are more 
economical than the coal range; and, except for the slightly dis- 
agreeable odor which accompanies their use, they are very satis- 
factory for domestic cooking. 

Electricity is not a substitute for coal; it is the ideal fuel 
for cooking. Its use is not accompanied by the many inconveni- 
ences which attend the use of the other fuels. The modern electric 
range is the most efficient cooking equipment available; and, if a 
suitable size is selected for a given family, it meets every re- 
quirement of domestic cooking. Here in the Northwest, where there 
is available an almost unlimited amount of water power for generat- 
ing electric energy, its use for domestic cooking cannot be too 
strongly urged, not only as a means of saving coal to meet the 
present war emergency but also as a means of conserving the sup- 
ply of coal and other fuels in time of peace. 


OTHER USEFUL BULLETINS 


1. The Economical Purchase and Use of Coal for Heating Homes 
with Special Reference to Conditions in Illinois. 1917. Engi- 
neering Experiment Station. Circular No. 4. Urbana, Illi- 
nois. Price 10 cents. 

2. Saving Fuel in Heating a Home. U. S. Bureau of Mines. Tech- 
nical Paper 97." 1915 

3. Fuel Tests with House-Heating Boilers. University of Illinois 
Engineering Experiment Station. Bulletin No. 31. Urbana, 
Hlinois. 1909. 

4. House Heating Fuel Tests. Iowa State College Engineering Ex- 
periment Station. Bulletin No. 33. Ames, Iowa, 1913. 

5. United States Bureau of Mines. Bulletin No. 22. 


vam FAMADY OF Tur 


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Amn .4A 1928 
ULL LJ jJ4ed 

NIVERSITY OF ILLINOIS 


14 


EXTENSION SERVICE BULLETINS 
by 
COLLEGE OF MECHANIC ARTS AND ENGINEERING 


How to Measure Water. 1915. 

Sewage Disposal for Country Homes. 1916. 

Water Supply for the Home. 1916. 

Cost of Pumping for Irrigation. 1916. 

Construction and Maintenance of Earth Roads. 1916. 


Address 


STATE COLLEGE OF WASHINGTON 
Pullman, Wash. : 


SAVE COAL 


SUBSTITUTE—WOOD, KEROSENE, ELECTRICITY 


SELECT THE RIGHT KIND OF HEATING AND 
COOKING EQUIPMENT 


WEIGH THE COAL YOU USE DAILY FOR A 
MONTH. 
and— ‘ 


LEARN TO FIRE YOUR PLANT ECONOMICALLY 


HEAT ONLY THE NECESSARY PART OF YOUR 
HOUSE 


PREVENT ALL UNNECESSARY HEAT LOSSES — 


